Improvement in screw-cutting machines



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L. YV. LANGDON, OF NORTHAMPTON, MASSACHUSETTS.

llVIPPLOVEh/IENT IN SCREW-CUTTING MACHINES.

Specification forming part oi' Letters Patent No. @5,0541, dated November l5, 1864.

To all whom t may volpe-erw,.-

Be it known that I, L. W. LANeDoN, of Northampton, in the county of Hampshire and State of Massachusetts, have invented Improvements in Screw-Cutting Machines; and l do hereby declare that the following, taken in connection with the drawings which accompany and form part of this specification, is a description of my invention sufcient to enable those skilled in the art to practice it.

My invention relates to sundry details of construction in machines designed for making screws such as are'used in gun-locks, sewingmachines, and elsewhere in mechanism generally, and it consists, first, in a peculiar construction of chuck by which the rod from which the screws are formed is centered and firmly held in any desired position, and is easily released from the grasp of the chuck, said construction rendering it as easy to perform such operations while the mandrel of the machine is in rotation as when it is still.

in the drawings, which are inclosed in a bracket and all embraced under the head of Figure l, may be found illustrations of this part of my invention. In this figure may be seen a plan, a longitudinal, and a cross section showing the chuck, its parts, and construction.

c is the hollow mandrel, the bore of which is at the end presented to the tail-stock enlarged eonica-lly, so as to receive the pieces marked b, one of which is shown in detail detached from its connection with the other parts. Three or more of these are used together, and are the pieces which come into contact with rod c to hold it, which is done by forcing pieces b into the conical cavity in a. To accomplish this movement the pieces d are driven toward the center of a by sliding forward the sleeve e, which is conical in the bore, and slips over the incline made on the outer ends of d. The inner ends of d being also inclined, as shown, and, meeting an ineline formed on b, forces b into a, and thus makes the pieces b pinch the rod c. When the sleeve e is slid in the other direction, centrifugal force, when the mandrel a is rotating, causes pieces d to move outward as far as permitted by their construction, and this leaves the parts b and rod free from stress.

j" is a screw-sleeve, which serves conven iently for the attachment and change of pieces d, and g is a check-nut to hold f in any desired position. This chuck is further seen in Fig. 2, which is a plan of the entire machine embodying the various parts of my invention; also, in Fig. 3, which is afront elevation ofthe machine seen in Fig. 2; also, in Fig. et, which is an end view ofthe head-stock in which the mandrel a rotates.

Another part of my invention consists in combining with the means by which the chuck is made to grip the rod c a gage by which the length of protrusion of c from the chuck is regulated. This is seen in Figs. 2, 3, and 4.

IL is a lever pivoted to the head-stock t', and gearing in the customary way into the sleeve e, so that vibration of the lever causes reciprocation ofthe sleeve. An arm, j, extends from lever h, as shown, on which a gage, 7c, is so placed as to be capable of sliding thereon and of being clamped in any desired position.

It will be obvious that when lever h is vibrated, as indicated by an arrow, that lo will be thrown down across the extension of the axis of a, so that before the rod c is clamped in the chuck its end will abut against gage 7r.

Means for economizing the quantity of lubricating-duid used upon the cutting-tools by making its iiow intermittent and confining it to such times as the tools are actually cutting may be employed as Jfollows:

Z is the receptacle for oil or other lubricator, from which a pipe, m, extends a suitable distance to bring its delivery over the place where the tool is cutting. In this pipe there is avalve made to close automatically by aspring or otherwise, which valvcis opened as the tail-stock bearing the tool is brought forward by the contact of the lever or handle of the valve with any suitable stop or incline-as, for example, the piece n, which is shown as adjustable so as to cause the valve to open at any desired point of the forward movement of the tail-stock.

The lubricator-reservoir and parts immediately therewith connected are shown in Fig. 5, which is an end view of the tail-stock, and also, together with the piece n, in Figs. 2 and 3.

The tail-stock is made up of three principal parts. Une is the carriage o, ar anged so that it can be slid on the bed-plate way, and there iixed in position as desired. This carriage has in its upper surface a dovetail groove iitted to receive the slide p, which can be reciprocated by working the levers seen in the plan, Fig. 2. 'lhe third part consists of a rotating toolholder, q, which is pivoted on slide p and moves with it.

The parto is clamped in position on the bed with reference to the work to be peformed, and then by its lever the slide p and tool holder q, provided with suitable tools, are advanced toward the headstock to the work. In withdrawing the slide and tool-holder the latter is rotated so as to present in the next forward movement of the slide another tool to operate on the work, and in the mechanism by which this rotation is accomplished maybe found another part of my invention. The tool holder has fixed in the part resting on the slide two series of pins, arranged in two circles concentric with the axis of rotation of the toolholder. The length of the outer row of pins is less than that of the inner row, so that in rotation they may pass over the swingfpiece r, (seen in Fi 6,) which is a section taken horizontally in the plane of the line a: a: seen in Fig. 5, and showing the slide in plan beneath. 'lhe number of pins in each circle corresponds with the number of socket-holes for tools in the holder, andthe pins are arranged as shown in Fig. 6. Those in the inner circle are brought into contact in the backward movement of the slide from the work with the swingpiece r, which is pivoted on the carriage o, and -with said swing-piece and the movement of the slide canse rotary movement of the tool-holder.

The pins in the outer circle, together with a latch, s, which is pivoted to the slide, form the means for lookin g the tool-holder and preventing it from rotating in its forward move` ment. ln drawing back the slide there is a pin, t, in the latch which comes into contact with the incline u, and this throws the latch s outward, unlocking from one of the outer circle of pins and leaving the tool-holder free to turn, when one ot' the inner circle of pins comes into contact with the swing-piece i', said piece being pivoted to enable it to swing to conform to the rotating movement ot' each inner pin away from the central line oi' the slide, which contact and the movement of the slide rotates the tool-holder, and in the retreating movement of the slide the pin t passes beyond the rea-r of the incline u, and lets the latch,impelled inward byaspring, rest against one of the outer row ot' pins, till in the continued rotation of the tool-holder, caused by further backward movement of the slide, said pin comes opposite the holding-notch in the latch, which snaps over said pin and locks the tool-holder in place for its advance movement by forward reoiprocation of the slide, in which movement the pin t passes the vincline u on the other side, said incline being so arranged as to spring aside under such movement of said pin.

In the tool-holder q are taper holes or sockets for reception of tool-shanks, which holes in number and spacing are made to correspond with the intermittentrotations of the tool-holder. rIhere is a stop-pin o fixed in the piece o, against which the adjustable screws w impinge and check the forward movement of the tool-holder. There is provided one ot' these screws for each tool-socket in the tool-holder, and it will be obvious that each tool can by these means have any de sired adjustment as to forward movement independent of the other tools, and in this arrangement of separate stops for each tool acting on one common rotating toolholder, to admit of different and determined extents of movement, consists another part of my invenA .to the center ofthe work which is rotated, and

thus insure a cutting action of the tool, which will 'without breakage of the work entirely and cleanly severit by cutting. To prevent yield ofthe work under the action of the cutter a', the shank which holds the faceplate b may be made hollow, so as to permit entrance and rotation therein of the partly-formed screws, and to the faceplate a back rest, may be secured so that it can be adjusted against the work and resist the thrust of the cuttingtool, and in this combination consists another part of my invention.

ln all screwcutting machines large quantities of Oil or other lubricatin g uids are used, and to prevent them from wasting by distribntion all over the tail-stock and surface of the bed, and to insure neatness, a groove may `be formed all around the `toprof `the carriage o, and one all around the top of the bed, in which the oil gathers as it falls ott' from the work and tools, and is conducted into any suitable receptacle, from which it maybe taken to be used again and again.

l claiml. In combination with a mechanism for cnttin g screws from wire, a chuck so arranged that the length of each screw may be adjusted while the machine is in motion.

2. The combination of an adjustable length gage with the means for operatin g the chuck, substantially as described.

3. Attaching the tool which outs off the screw to the revolving head, thereby dispens ingl with the ordinary cross-head.

4. In combination with a rotating toolcar rier, the means for intermittently operating the same, when arranged substantially as described.

5. The arrangement of an adjustable stop with each socket in a rotating tool-holder, so that by the operation of said stops on some fixed part of the tail-stock each tool may be separately and easily adjusted as to its own extent of forward movement.

L. W. LANGDON.

Witnesses DAVID E. GRIMEs, CHARLES STRANG. 

